CN112236260B

CN112236260B - Method and apparatus for manufacturing annular band saw tooth

Info

Publication number: CN112236260B
Application number: CN201980038539.7A
Authority: CN
Inventors: 前田健作
Original assignee: Tiantian Machinery Co ltd; Tian Tian Group Co ltd
Current assignee: Tiantian Machinery Co ltd; Tian Tian Group Co ltd
Priority date: 2018-06-08
Filing date: 2019-06-03
Publication date: 2023-06-27
Anticipated expiration: 2039-06-03
Also published as: EP3804894A1; US11925994B2; EP3804894A4; EP3804894B1; US11607739B2; JP2019209456A; US20230191512A1; CN112236260A; WO2019235404A1; US20210260674A1; JP6578412B1

Abstract

The circularization step is performed by welding both ends of a band saw tooth (1) having a band-shaped main body (1 a) and a tooth portion (1 b) including a plurality of teeth formed on one side portion of the main body. The polishing step polishes the inner surface (14A) and the outer surface (14B) of the annular band saw tooth (1E) which are cyclized and the end surface (13) on the side opposite to the tooth part. The blade tooth tip forming step is to position the annular band saw tooth having undergone the annular ring forming step with reference to one of the inner surface and the outer surface and the end surface, join the cutting blade (15) to the tooth tip of the tooth by welding, and grind the joined cutting blade to form the tooth tip shape.

Description

Method and apparatus for manufacturing annular band saw tooth

Technical Field

The present invention relates to a method and an apparatus for manufacturing annular band saw teeth.

Background

Japanese patent laid-open publication No. 2012-035383 (patent document 1) exemplifies a method of polishing a serrated cutting insert having a hard cutting insert at the tip. Further, japanese patent application laid-open No. 2013-010170 (patent document 2) exemplifies a method of manufacturing continuous (annular) band saw teeth at both ends of a butt-welded band saw tooth by flash welding, which is one type of resistance welding.

In the case of manufacturing a ring-shaped band saw tooth using a band saw tooth having a hard cutting blade at the tooth tip, the following method is generally used. First, a predetermined length of serrated tooth tip before cyclization engages the cutting insert by welding or the like. Then, the joined cutting insert is ground with a diamond grinding wheel, and formed into a predetermined tooth tip shape. Then, the annular band saw teeth are formed by resistance welding both ends of the band saw teeth.

In this method, the grinding operation of the cutting insert is performed in a state in which one surface of the main body is abutted against the table with the end of the tooth tip and the end of the main body opposite to the tooth tip as a reference for positioning, and the belt saw teeth are sandwiched by the tiger head pliers.

However, the main body portion may be deformed in the width direction and the thickness direction by heat treatment during the production of the belt saw teeth. Depending on the degree of this deformation, the following problems arise: the precision of the shapes of the plurality of tooth tips formed by the polishing operation is lowered, or the unevenness of the shapes among the plurality of tooth tips becomes large.

When such a ring-shaped band saw tooth is used for machining, there is a risk that the quality of the cut surface is lowered.

In addition, the joined portion obtained by the circularization is likely to bulge accompanying the welding, and when bulge occurs, an operation of flattening by grinding with a grinder or the like is performed. However, due to uneven grinding, slight irregularities tend to remain on the surface of the main body, and when band saw teeth having irregularities remaining in the joint are used for cutting, spiral cutting marks are generated on the cut surface of the product, and the quality of the cut surface may be degraded.

Thus, there is a need for annular belt serrations that can achieve good cut surface quality.

Disclosure of Invention

Problems to be solved by the invention

According to the present invention, a method and an apparatus for producing annular band saw teeth, which can obtain good quality of cut surfaces, can be provided.

Means for solving the problems

According to an aspect of the present invention, a method for manufacturing an endless belt saw tooth is characterized by comprising: a step of circularizing by welding both ends of a band saw tooth having a band-shaped main body portion and a tooth portion including a plurality of teeth formed on one side portion of the main body portion; a polishing step of polishing an inner surface and an outer surface of the band saw tooth subjected to the circularization, the end surface being on the side opposite to the tooth portion; and a blade tooth tip forming step of positioning the annular toothed teeth with respect to either one of the inner surface and the outer surface and the end surface after the polishing step, joining cutting blades to the tooth tips of the plurality of teeth by welding, and polishing the joined cutting blades to form a tooth tip shape.

According to another aspect of the present invention, an apparatus for manufacturing an annular band saw tooth, which manufactures an annular band saw tooth having a hard cutting blade joined to a tooth tip, includes: a circulating movement part for circulating the annular band saw teeth having a band-shaped main body part and a tooth part, wherein the tooth part comprises a plurality of teeth formed on one side part of the main body part; a surface polishing unit configured to polish an inner surface and an outer surface of the body portion of the annular belt saw tooth that is circulated by the circulation unit; and an end face polishing unit configured to polish an end face of the main body portion of the annular belt saw tooth that is moved in a circulating manner by the circulating unit, the end face being on a side opposite to the tooth portion.

Drawings

Fig. 1 is a first diagram for explaining a manufacturing step of an annular band saw blade 1E according to an example of a manufacturing method of an annular band saw blade according to an embodiment of the present invention.

Fig. 2 is a second diagram for explaining a manufacturing step of the annular band saw tooth 1E.

Fig. 3 is a plan view showing an example of a polishing apparatus 81 as an apparatus for manufacturing an endless belt saw blade according to an embodiment of the present invention.

Fig. 4 is a cross-sectional view of the S4-S4 position in fig. 3.

Fig. 5 is a view for explaining a cross-sectional view of the surface polishing section 2 and the end surface polishing section 3 of the polishing apparatus 81, which corresponds to positions S5 to S5 in fig. 4.

Fig. 6 is a view illustrating polishing areas FA1 and FB1 of the annular belt saw tooth 1E at the initial stage of the polishing step, where fig. 6 (a) is an inner surface 14A and fig. 6 (B) is an outer surface 14B.

Fig. 7 is a diagram for explaining an example of the state of the polishing areas FA2, FB2 of the annular belt saw tooth 1E after the polishing step is performed, in which fig. 7 (a) is an inner surface 14A and fig. 7 (B) is an outer surface 14B.

Fig. 8 is a functional configuration diagram for explaining a state of a joining operation of the blade joining device 91 to join the tooth portion 1b to the cutting blade 15 after the polishing step is performed.

Fig. 9 is a graph showing the roughness of the cut surfaces of examples and comparative examples.

Detailed Description

An example of a method for manufacturing the annular band saw tooth according to the embodiment of the present invention will be described with reference to the steps for manufacturing the annular band saw tooth 1E.

In this manufacturing step, a polishing apparatus 81 shown in fig. 3 is used as an example of the manufacturing apparatus for the annular belt saw blade according to the embodiment of the present invention.

The annular band saw blade 1E is formed in an annular shape, and is a band saw blade that can be continuously and circularly moved by a general band saw blade. The belt saw tooth 1 before the circularization has: a band-shaped main body portion 1a; and a tooth portion 1b (fig. 1) including a plurality of teeth formed on one side portion of the main body portion 1a.

First, as shown in fig. 1, a band-shaped band saw tooth 1 having a main body portion 1a and a tooth portion 1b is formed in a wheel shape, and one end 11 and the other end 12 are disposed to face each other.

In this state, the surface of the main body 1a that is the inner side of the wheel is the inner surface 14A, and the surface that is the outer side is the outer surface 14B. The end face of the main body 1a opposite to the tooth 1b is an end face 13.

The belt serrations 1 have not yet engaged the cutting insert 15 (see fig. 8).

(cyclization step)

Next, as shown in fig. 2, the end 11 and the end 12 are joined by welding to be looped. That is, the belt saw blade 1 is formed as an annular belt saw blade 1E. The method of welding uses a known method such as resistance welding used for the toothed ring formation.

In the annular band saw tooth 1E, a portion where the end portion 11 and the end portion 12 are joined is referred to as a joint portion 1Ea. A heat affected zone F, which is likely to be deformed by the influence of heating accompanying welding, is formed in the vicinity of the joint 1Ea as indicated by oblique lines.

The annular band saw blade 1E is attached to a polishing device 81 as an annular band saw blade manufacturing device shown in fig. 3, and performs polishing of a predetermined portion. The predetermined portion is an end face 13, an inner surface 14A, and an outer surface 14B of the main body portion 1a.

The polishing device 81 will be described with reference to fig. 3 to 5. The polishing device 81 has a driving wheel 6 and a driven wheel 7. The operator hangs the annular belt saw teeth 1E to be polished on the driving wheel 6 and the driven wheel 7.

The drive wheel 6 has a motor 61. The motor 61 rotates along an arrow DR61 shown in fig. 3 to circulate the hanging endless belt saw tooth 1E in a clockwise direction (arrow DR 1) in fig. 3.

The driven pulley 7 has a back tension imparting portion 71. The back tension applying section 71 outputs a rotational driving force in the direction of a broken line arrow DR71 in fig. 3.

Thereby, a predetermined back tension is applied to the endless belt saw tooth 1E that is moved circularly. Thus, a circulating movement portion 67 including the driving wheel 6 and the driven wheel 7 and circulating the endless belt saw tooth 1E is formed.

The polishing device 81 includes an upstream guide portion 5, a surface polishing portion 2, a downstream guide portion 4, and an end surface polishing portion 3 on the circulating path of the endless belt saw blade 1E from the upstream side.

The upstream guide portion 5 and the downstream guide portion 4 have the same structure and are disposed in the vicinity of the upstream side and the downstream side of the surface polishing portion 2, respectively. The upstream guide portion 5 includes an inner guide portion 5A for guiding the inner surface 14A and an outer guide portion 5B for guiding the outer surface 14B so as to sandwich the endless belt saw tooth 1E that is cyclically moved in the thickness direction. The downstream guide portion 4 includes an inner guide portion 4A for guiding the inner surface 14A and an outer guide portion 4B for guiding the outer surface 14B so as to sandwich the endless belt saw tooth 1E that is cyclically moved in the thickness direction.

Thereby, the vibration in the thickness direction when the annular belt saw teeth 1E circulate through the surface polishing section 2 is suppressed to a substantially negligible extent.

The surface polishing section 2 includes: an inner polishing section 2A disposed in correspondence with the inner surface 14A of the annular belt serration 1E and polishing the inner surface 14A; and an outer polishing section 2B disposed in correspondence with the outer surface 14B and polishing the outer surface 14B.

The inner grinding section 2A includes a grinding wheel 21A, a shaft 23A, and a motor 22A. The outer grinding section 2B includes a grinding wheel 21B, a shaft 23B, and a motor 22B.

That is, the surface grinding section 2 includes a pair of grinding

wheels

21A, 21B.

The grinding wheel 21A has a disk-shaped base 21A1 and a circular grindstone 21A2 mounted on the periphery thereof. The circular grindstone 21A2 is, for example, annular.

The rotation axis CL2A of the grinding wheel 21A is inclined by an inclination angle θa toward the front side (downstream side) in the circulating movement direction with respect to the inner surface 14A of the annular belt saw tooth 1E, and is orthogonal with respect to the width direction (see fig. 5).

The grinding wheel 21A is fixed in a posture orthogonal to the rotation axis CL2A at the tip of the shaft 23A extending along the rotation axis CL 2A. The shaft 23A is rotatably connected to an output shaft of the motor 22A via a pressing portion 24A. The pressing portion 24A presses the shaft 23A by the action of a compression spring or the like so that the grinding wheel 21A is pressed against the inner surface 14A by the urging force fA.

By driving the motor 22A, the grinding wheel 21A rotates while bringing the circular grinding stone 21A2 into contact with the inner surface 14A. The rotation direction of the motor 22A is a direction in which the grinding wheel 21A is set to move forward in the circulating direction (counterclockwise in fig. 4: see arrow DR 2), that is, from the tooth portion 1b toward the end face 13. The direction is the grinding direction.

Thus, the circular grindstone 21A2 is ground while pressing the front end portion of the annular belt saw tooth 1E on the front side in the circulating direction against the inner surface 14A with a predetermined force fA.

The grinding wheel 21B has a disk-shaped base 21B1 and a circular grindstone 21B2 mounted on the periphery thereof. The circular grindstone 21B2 is, for example, annular. The rotation axis CL2B of the grinding wheel 21B is inclined by an inclination angle θb to the front (downstream side) of the outer surface 14B of the annular belt saw tooth 1E in the moving direction as the belt direction and is orthogonal to the width direction (see fig. 5).

The grinding wheel 21B is fixed in a posture orthogonal to the rotation axis CL2B at the tip of the shaft 23B extending along the rotation axis CL 2B. The shaft 23B is connected to an output shaft of the motor 22B via a pressing portion 24B, and is rotatable. The pressing portion 24B presses the shaft 23B so that the grinding wheel 21B presses against the outer surface 14B with the force fB.

By driving the motor 22B, the grinding wheel 21B rotates while bringing the circular grinding stone 21B2 into contact with the outer surface 14B. The rotation direction of the motor 22B is a direction in which the grinding wheel 21B is set to the front side in the circulating direction (the direction synchronous with the grinding wheel 21A), that is, the direction from the tooth portion 1B toward the end face 13. The direction is the grinding direction.

Thus, the circular grindstone 21B2 grinds the annular band saw teeth 1E while pressing the front end portion on the front side in the circulating direction against the outer surface 14B with a predetermined force fB.

As shown in fig. 5, the rotation axes CL2A and CL2B are located at the same position in the width direction (up-down direction in fig. 5) of the annular band saw tooth 1E, and are set at the center position of the full width Wa where the main body portion 1a and the tooth portion 1B of the annular band saw tooth 1E are added up.

The end face polishing section 3 is disposed on one of the front and rear sides of the surface polishing section 2 in the circulating movement direction of the annular belt saw tooth 1E.

In this example, the end face polishing portion 3 is disposed on the downstream side (front side) of the downstream guide portion 4 so as to face an end face 13 on the opposite side of the annular belt serration 1E from the tooth portion 1b. The end face grinding section 3 has a cup-shaped cup grindstone 31 and a motor 32.

The motor 32 rotates the cup grindstone 31 in an arbitrary direction about the rotation axis CL 3. The rotation axis CL3 extends in the orthogonal direction with respect to the end face 13 of the annular band saw tooth 1E.

The polishing device 81 having the above-described structure polishes the inner surface 14A and the outer surface 14B of the annular band saw tooth 1E with the surface polishing section 2, and polishes the end face 13 of the annular band saw tooth 1E with the end face polishing section 3.

Each polishing will be specifically described.

The operator hangs an annular band saw tooth 1E formed in an annular shape at both ends of the engaged band saw tooth 1 on the driving wheel 6 and the driven wheel 7. At this time, the annular belt saw tooth 1E is passed between the inner guide portion 5A and the outer guide portion 5B of the upstream guide portion 5, between the grinding wheel 21A and the grinding wheel 21B of the surface grinding portion 2, and between the inner guide portion 4A and the outer guide portion 4B of the downstream guide portion 4.

The polishing device 81 is configured to bring the end surface 13 of the annular belt saw tooth 1E into contact with the annular front end surface 31a of the cup grindstone 31 while the annular belt saw tooth 1E is engaged with the driving wheel 6 and the driven wheel 7.

The operator drives the motor 61 to rotate the driving wheel 6, and cyclically moves the endless belt saw blade 1E in the direction of arrow DR1 in fig. 3. As the motor 61 is driven, the back tension applying section 71 also operates to apply a predetermined back tension to the endless belt saw tooth 1E. Thereby, the endless belt saw tooth 1E stably and circularly moves in a moderately stretched state.

The operator drives the

motors

22A, 22B, 32. Thereby, the circular grindstones 21A2, 21B2 and the cup grindstone 31 rotate, and grinding of the inner surface 14A, the outer surface 14B and the end face 13 is performed, respectively.

As described above, the rotation direction of the circular grindstones 21A2, 21B2 is set so that the forward end side in the straight direction is downward (arrow DR 2) in fig. 4. Thereby, a downward force is applied to the annular belt saw teeth 1E at the surface grinding portion 2. Therefore, in the end face grinding section 3 located on the downstream side of the face grinding section 2, the end face 13 stably biases the cup grindstone 31. Therefore, the end face 13 is reliably and well polished by the cup grindstone 31.

In addition, the cup grindstone 31 rotates, and therefore the front end face 31a of the cup grindstone 31 is uniformly used for grinding of the end face 13. Thereby, the wear of the cup grindstone 31 is not biased in the circumferential direction but averaged. Therefore, the polishing amount of the end face 13 is also uniformed every one round, and the end face 13 is polished well.

The polishing regions on the inner surface 14A and the outer surface 14 of the annular belt saw tooth 1E, which are the regions polished by the surface polishing section 2, change with polishing time and expand in the width direction. This variation will be described with reference to fig. 6 (a), 6 (b), and 7 (a) and 7 (b).

Even when the heat affected zone F in the vicinity of the joint portion 1Ea joined to form a ring shape bulges, the bulge is polished and removed by the surface polishing portion 2, and flattening is performed.

Fig. 6 (a) and 6 (B) show polishing areas FA1 and FA2 at the initial stage of the start of polishing of the inner surface 14A and the outer surface 14B, respectively, in diagonal line ranges. Specifically, the polishing areas FA1 and FA2 are polished by abutting only the downstream tip portions of the grinding

wheels

21A and 21B, respectively, at the beginning of polishing, and the height position P1 of half the full width Wa (Wa/2) is centered from the end surface 13 toward the tooth portion 1B.

The polishing areas FA1, FB1 expand at substantially the same rate toward the tooth portion 1B side and the opposite side thereof as the polishing proceeds by the cyclic movement of the annular belt saw tooth 1E and the urging contact of the circular grindstones 21A2, 21B2.

The polishing depth (polishing amount) is set to 0.02 to 0.03mm in the width direction of the main body 1a toward the center. For example, when the thickness of the main body 1a is 1.60mm to 1.61mm before polishing, the thickness of the widthwise central portion is set to about 1.58 mm.

When the polishing amount of the widthwise central portion is 0.02 to 0.03mm, the following items are set in advance so that substantially the entire surfaces of the inner surface 14A and the outer surface 14B are polished. In detail, the set inclination angles θa, θb, the diameters DA, DB (fig. 3) of the circular grinding stones 21A2, 21B2, the rotation speeds VA, VB, and the like are adjusted in advance as exemplified below.

Diameter DA:150mm, diameter DB:150mm

Rotational speed VA:1500 rpm, rotation speed VB:1500 rpm

Inclination angle θa: about 0.8 ° (0.5 ° -1.0 °), inclination angle θb: about 0.8 degree (0.5 degree to 1.0 degree)

The annular band saw tooth 1E has a relatively small thickness relative to the full width Wa, and the thickness relative to the full width Wa is generally about 3 to 5%. Accordingly, as the polishing proceeds, the circular grindstones 21A2, 21B2 may become recessed in the thickness direction with respect to the annular belt saw teeth 1E, and the edges on the tooth portion 1B side and the opposite side may bend toward one of the circular grindstones 21A2, 21B2 as indicated by an arrow DR3 in fig. 5.

The polishing areas FA2 and FB2 at the polishing end time in this case are shown in fig. 7 (a) and 7 (b), respectively. Here, a case will be described in which the annular band saw teeth 1E are curved toward the circular grindstone 21B2 side of the grinding outer surface 14B and are ground. That is, substantially the entire surface of the outer surface 14B including the tooth portion 1B is ground due to the circular grindstone 21B2 on the curved curvature center side.

On the other hand, the curved side opposite to the curvature center does not contact the circular grindstone 21A2 in the tooth portion 1b side region and the both edge regions on the end face 13 side in the width direction, and becomes non-grinding regions FA3 and FA4 as minute grinding residue regions. Of course, bending may not occur, and in this case, the entire surfaces of the inner surface 14A and the outer surface 14B become the polishing areas FA2 and FB2, respectively.

(blade tooth tip Forming step)

The cutting blade 15 is engaged with the annular band saw tooth 1E polished by the polishing device 81 by the blade engagement device 91. Fig. 8 is a functional configuration diagram showing the blade engagement device 91. The cutting insert 15 is formed of a hard material such as cemented carbide.

The blade bonding device 91 is a resistance welding device, and includes a pedestal 92, a main body electrode 93, a blade electrode 94, a welding power source 95, and

drivers

96 and 97. The pedestal 92 positions and supports the annular band saw blade 1E by the main body receiving portion 921 and the end surface receiving portion 922.

Specifically, the operator urges the body receiving portion 921 to abut against the polishing area FA2 of the inner surface 14A or the polishing area FB2 of the outer surface 14B of the body portion 1a of the annular toothed belt 1E. The end surface receiving portion 922 is biased to abut the end surface 13 of the main body portion 1a of the annular band saw blade 1E.

The main body electrode 93 is biased by the driver 96 to abut against the inner surface 14A of the main body 1a of the annular band saw blade 1E, and presses the main body 1a against the main body receiving portion 921 of the pedestal 92 (arrow DR 4).

The blade electrode 94 is biased by a driver 97 to abut against the cutting blade 15 carried by the tip end portion of the tooth portion 1b of the annular band saw tooth 1E, and presses the cutting blade 15 against the tooth portion 1b.

The main body electrode 93 and the blade electrode 94 are connected to a welding power source 95. The welding power supply supplies a welding current of a predetermined value to the space between the main body electrode 93 and the blade electrode 94 for a predetermined time. Then, the contact portion between the blade electrode 94 and the tip of the tooth portion 1b is melted by resistance heat, and cooled and solidified after stopping the energization. Thereby, the blade electrode 94 is bonded to the tooth portion 1b.

Thereafter, the body electrode 93 and the insert electrode 94 are separated, and the bonded cutting insert 15 is polished with a diamond wheel to form a predetermined edge shape.

In this joining operation and the formation of the tooth tip shape of the joined cutting insert 15, the device to be polished 81 with the annular saw tooth 1E is positioned at the reference position over the end face 13 and the outer face 14B polished over the entire circumference of the annular shape.

Therefore, the positions of the plurality of tips of the tooth portion 1b positioned are stably determined with high accuracy, and therefore the tip shape of the cutting insert 15 formed by the grinding operation is formed with high accuracy. In addition, the unevenness of the shape of the full tooth tip of the annular band saw tooth 1E is suppressed to be small.

Further, the polishing device 81 polishes the entire surface of one of the inner surface 14A and the outer surface 14B of the body portion 1a of the annular toothed portion 1E and the entire surface of the other. Thus, the irregularities on the surface are suppressed to a level that can be substantially ignored throughout the entire circumference of the ring.

Therefore, when the annular band saw tooth 1E manufactured by using the polishing device 81 is used for cutting, no circumferential cutting mark is generated on the cut surface of the product, and there is no problem that the quality of the cut surface is degraded.

Fig. 9 is a graph showing the roughness of the cut surface when the following two materials are cut by a general band saw blade using the annular band saw blade 1E manufactured by the method of the above-described example and the annular band saw blade 1EP manufactured by the method related to the comparative example. The roughness of the cut surface was evaluated by Ra (arithmetic average roughness) and Rz (maximum height roughness).

The related method as comparative example successively performed the joining of the cutting insert, the formation of the tooth tip of the cutting insert, the joining of the ring shape, and the removal of the bulge of the joined portion by the grinder.

The materials to be cut are two of the following materials a and B.

A material: S45C (carbon steel for mechanical construction) round bar material diameter 50mm

Material B: SUJ2 (high carbon chromium bearing Steel) round bar material diameter 70mm

The cutting conditions are common to the materials a and B, and are as follows.

Saw speed: 200m/min

Cutting time: 4 seconds

The cut surface roughness represents the average value of Ra and Rz at three points, that is, a position near the start of cutting, a position in the middle of cutting (the center of the round bar), and a position near the end of cutting, of the cut surface, measured by using a surface roughness measuring instrument "SJ-210" manufactured by Sanfeng corporation.

As shown in fig. 9, ra is conventionally 3.53 (μm) and 3.77 (μm) in S45C, SUJ, respectively, but is reduced to 0.64 (μm) and 0.62 (μm) in the examples.

Rz is conventionally 19.82 (μm) and 19.69 (μm) in S45C, SUJ2, respectively, but is reduced to 3.53 (μm) and 3.19 (μm) in the examples.

In addition, under visual observation of the cut surface, in the comparative example, a slight mark was confirmed, while in the example, no mark was confirmed.

That is, it is apparent that the continuous toothed manufacturing method according to the example can reduce the surface roughness of the cut surface as compared with the conventional method, and can prevent the occurrence of the cutting mark, thereby obtaining a good cut surface quality.

The surface polishing section 2 of the polishing apparatus 81 polishes the inner surface 14A and the outer surface 14B of the annular saw tooth 1E with the circular grindstone 21A2 and the circular grindstone 21B2, respectively.

In the polishing operation, the polishing device 81 rotates the circular grindstone 21A2 and the circular grindstone 21B2 about the rotation axes CL2A and CL2B set non-perpendicularly to the inner surface 14A and the outer surface 14B, respectively. The rotation direction is set so that the polishing direction is a direction from the tooth portion 1b toward the end face 13.

Thus, at the initial stage of the polishing operation, the circular grindstone 21A2 and the circular grindstone 21B2 are biased to contact the inner surface 14A and the outer surface 14B, respectively, at their peripheral edges. Therefore, the area of a part of the annular belt saw teeth 1E in the width direction is polished in a thin belt shape as the polishing areas FA1 and FB1, and the widths of the polishing areas FA1 and FB1 are increased as the polishing operation proceeds. Therefore, the operator can visually grasp the progress of polishing.

Further, by setting the rotation axes CL2A and CL2B at substantially the center positions in the width direction of the annular belt saw tooth 1E, the polishing areas FA1 and FB1 are uniformly enlarged toward the tooth portion 1B side and the end face 13 side without being biased. Therefore, the possibility of excessively polishing the first polished polishing region FA1 and the first polished polishing region FB1 in order to polish the entire surface is small.

In addition, by the above setting of the rotation direction, the end face 13 is biased to contact the cup grindstone 31 of the end face grinding portion 3, and therefore the end face 13 can be ground stably and satisfactorily.

The embodiment of the present invention is not limited to the above-described configuration and steps, and modifications may be adopted within a range not departing from the gist of the present invention.

Before the belt saw tooth 1 is cyclized, the cutting blade 15 may be joined as follows to form a tooth tip, and then the belt saw tooth may be cyclized.

The steps in this case are as follows, for example.

First, both surfaces of the body portion 1a and the end face 13 on the opposite side to the tooth portion 1b are polished (first polishing) in a state of the belt-like saw tooth 1 before the ring formation. Then, the cutting insert 15 is welded to one of the two surfaces to be ground and the end surface 13, and the tooth tip shape is formed. Then, the one end 11 and the other end 12 of the band saw tooth 1 to which the cutting blade 15 is bonded are welded together to form an annular band saw tooth 1E. Thereafter, both surfaces of the annular body portion and the end face 13 on the opposite side to the tooth portion are polished (second polishing).

In this case, two polishing steps are required, but polishing of both surfaces and end surfaces 13 of the body portion 1a is performed as a first step before the cutting insert 15 is joined to the tooth portion 1b and the shape is formed, and polishing of flattening irregularities of the joined portion 1Ea is performed as a second step after the annular shape is formed. Thus, the tooth tip shape of the cutting insert 15 is formed with high accuracy and uniformity, and the joining portion 1Ea is substantially free from irregularities, so that a good quality of the cut surface can be obtained.

The structures of the

pressing portions

24A, 24B for biasing the circular grindstones 21A2, 21B2 against the annular belt saw teeth 1E are not limited, and a known biasing structure can be applied. The polishing apparatus 81 may include a motor control unit that controls the rotation of the motor 22A and the rotation of the motor 22B to be opposite in direction and to synchronize the speeds. The

motors

22A and 22B may be separated into two systems on the force transmission path by using one motor as a driving source.

The circular grindstones 21A2, 21B2 provided in the grinding

wheels

21A, 21B are not limited to annular shapes as long as the outer shape is circular. For example, a disc-shaped flat grindstone may be used. The rotation axes CL2A, CL B of the grinding

wheels

21A, 21B may not be necessarily located at the center in the width direction of the annular band saw tooth 1E, but may be located at a position offset to the tooth portion 1B side or the end face 13 side.

As described in the embodiment, by inclining the rotation axis CL2A, CL B in the circulating direction at the center in the width direction, the progress degree of polishing can be grasped by the expansion degree of the polishing areas FA1, FA2 in the width direction.

As described above, according to the present invention, an effect that a good cut surface quality can be obtained.

(specification in the United states)

The international patent application relates to U.S. designations, and is incorporated herein by reference for the benefit of priority requirements of U.S. patent laws 119 (a) in connection with the national patent application No. 2018-110240 of the 2018 6-8 application.

Claims

1. A method of manufacturing an endless belt saw tooth, comprising:

a step of circularizing by welding both ends of a band saw tooth having a band-shaped main body portion and a tooth portion including a plurality of teeth formed on one side portion of the main body portion;

a polishing step of polishing an inner surface and an outer surface of the band saw tooth subjected to the circularization, the end surface being on the side opposite to the tooth portion; and

and a blade tooth tip forming step of positioning the annular toothed teeth with respect to either one of the inner surface and the outer surface and the end surface after the polishing step, joining cutting blades to the tooth tips of the plurality of teeth by welding, and polishing the joined cutting blades to form a tooth tip shape.

2. The method of manufacturing an endless belt saw tooth according to claim 1, wherein,

the polishing step is performed by rotating the circular grindstone relative to the inner surface and the outer surface, respectively, while circulating the band saw teeth having been subjected to the circularization, and applying a force thereto.

3. The method of manufacturing an endless belt saw tooth according to claim 2, wherein,

a grinding stone for grinding the end surface is arranged at one side of the front and rear of the main body part relative to the circular grinding stone in the circulating movement direction,

the rotation axis of the circular grindstone is inclined toward the one side in the center of the main body in the width direction,

the rotation direction of the circular grindstone is set so that the grinding direction is directed from the tooth portion in the width direction of the main body portion toward the end face.

4. An annular toothed polishing device for polishing an annular toothed having a hard cutting blade joined to a tooth tip, the annular toothed polishing device comprising:

a circulating movement section configured to circulate an endless belt saw tooth having a belt-shaped main body section and a tooth section, the tooth section including a plurality of teeth formed on one side of the main body section, the circulating movement section including a driving wheel and a driven wheel, the endless belt saw tooth being suspended from the driving wheel and the driven wheel, the driving wheel configured to circulate the endless belt saw tooth along an endless circulating movement path, the driven wheel configured to impart a predetermined back tension to the endless belt saw tooth that is circulated;

a surface polishing unit configured to polish an inner surface and an outer surface of the body portion of the annular belt saw tooth that is circulated by the circulation unit; and

and an end face polishing unit configured to polish an end face of the main body portion of the annular belt saw tooth that is moved in a circulating manner by the circulating unit, the end face being on a side opposite to the tooth portion.

5. The apparatus of claim 4, wherein the apparatus further comprises a plurality of rollers,

the surface grinding part is provided with a pair of rotatable round grindstones which are respectively arranged corresponding to the inner surface and the outer surface,

the pair of circular grindstones are rotated while being brought into contact with the inner surface and the outer surface of the endless belt saw tooth, respectively, to polish the same.

6. The polishing apparatus with saw teeth according to claim 5, wherein,

the end surface polishing part is disposed on one side of the front and rear sides of the circulating movement with respect to the surface polishing part,

the rotation axes of the pair of circular grindstones are set to be inclined toward the one side at the center in the width direction of the main body portion,

the rotation direction of each of the pair of circular grindstones is a direction in which the grinding direction is directed from the tooth portion in the width direction of the main body portion toward the end face.